1. Field of the Invention
The present invention relates to a vital information measuring device for measuring vital information such as an arterial blood oxygen saturation or a pulse rate.
2. Description of the Related Art
There is used a pulse oximeter in the field of diagnosing a sleep apnea syndrome (SAS) (see U.S. Pat. No. 4,955,379 corresponding to Japanese Unexamined Patent Publication No. 1-153139/1989, for instance). The pulse oximeter has a measuring unit which is detachably attached to a predetermined measurement site of a living body i.e. a subject. The measuring unit is constructed in such a manner that light is outputted toward the measurement site of the living body, and an oxygen saturation (SpO2) in blood of the measurement site is measured based on the amount of light transmitted through or reflected from the measurement site.
Also, the pulse oximeter is communicable with an external device e.g. a personal computer incorporated with a predetermined program. For instance, when data concerning a blood oxygen saturation (hereinafter, called as “blood oxygen saturation data”) obtained from a subject by overnight pulse oximetry is outputted from the pulse oximeter to the personal computer, the program in the personal computer is activated to calculate an ODI (Oxygen Desaturation Index), which represents a change in blood oxygen saturation with time, or the number of times when the blood oxygen saturation is lowered than a predetermined threshold value per unit time, based on an average of the measurement data.
In the conventional art, a user of the pulse oximeter is required to connect the pulse oximeter to the personal computer, and to designate an operation of acquiring the ODI using the personal computer. In this arrangement, the ODI cannot be promptly confirmed after the measurement is completed. Also, the above operation is cumbersome for the user.